Cross cell interference is a problem in wireless communication systems. FIG. 1 is an illustration of cross cell interference. As illustrated, a wireless transmit/receive unit (WTRU) 241 is located at the periphery of cell 1 261 and another WTRU 242 is located near that WTRU 241 at the periphery of another cell, cell 2 262. The WTRU 241 of cell 1 261 transmits an uplink communication U1 to its base station 201 and the WTRU 242 of cell 2 262 is receiving a downlink communication, D2, from its base station 202. If the uplink communication U1 and the downlink communication D2 are sent in the same spectrum and at the same time, the uplink communication U1 interferes with the downlink communication D2's reception. Typically, to overcome the interference in its downlink communications, the WTRU 242 will request an increase in transmission power from its base station 202. The increase in transmission power results in increased interference to other WTRUs in and outside its cell 262.
An alternative method of link adaptation is adaptive modulation and coding (AM&C), in which coding and modulation are adjusted to reduce the information data rate in the presence of inter-cellular interference. AM&C decreases the data throughput in the affected WTRU.
In many wireless communication systems, techniques for reducing interference within a cell are employed. Some of these approaches include successive interference cancellers (SICs), parallel interference cancellers (PICs) and multi-user detectors (MUDs). Although these techniques are effective at canceling the intra-cell interference, they treat inter-cell interference as noise.
Accordingly, it is desirable to reduce inter-cell interference.